Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun air_sac

3 senses of air sac

Sense 1
alveolus, air sac, air cell -- (a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways)
       => sac -- (a structure resembling a bag in an animal)

Sense 2
air sac -- (any of the thin-walled extensions of the tracheae of insects)
       => sac -- (a structure resembling a bag in an animal)

Sense 3
air sac -- (any of the membranous air-filled extensions of the lungs of birds)
       => sac -- (a structure resembling a bag in an animal)